The influence of scene and object orientation on the scene consistency effect.

Contextual regularities help us make sense of our visual environment. In scenes, semantically consistent objects are typically better recognized than inconsistent ones (e.g., a toaster vs. printer in a kitchen). What is the role of object and scene orientation in this so-called scene consistency effect? We presented consistent and inconsistent objects either upright (Experiment 1) or inverted (rotated 180°; Experiment 2) on upright, inverted, and scrambled background scenes. In Experiment 1, on upright scenes, consistent objects were recognized with higher accuracy than inconsistent ones, and we observed N300/N400 event-related potentials (ERPs) reflecting object-scene semantic processing. No such effects were observed for inverted or scrambled scenes. In Experiment 2, on both upright and inverted scenes, consistent objects were recognized with higher accuracy than inconsistent ones. Moreover, inconsistent objects on upright scenes triggered N300/N400 responses. Interestingly, no N300 but only an N400 deflection was found for inconsistent objects on inverted scenes. No effects were observed for scrambled scenes. These data suggest that while upright scenes modulate recognition irrespective of object orientation, inverted scenes only modulate the recognition of inverted objects. In ERPs, we found further evidence that inverted scenes can affect semantic object processing, with contextual influences occurring later in time, possibly driven by delayed or impaired scene gist processing. Mere object inversion does not seem to explain the later emergence of contextual influences. Taken together, the results suggest that the orientation of objects and scenes as well as their relationship to each other can influence ongoing object identification.